Known piezoelectric actuators include a piezoelectric element including first and second main surfaces opposing each other and a supporting member supporting the piezoelectric element (for example, refer to Japanese Unexamined Patent Publication No. 2012-155832). In the piezoelectric actuator described in Japanese Unexamined Patent Publication No. 2012-155832, an actuator base of a suspension for a hard disk device (HDD) corresponds to the above-described supporting member, and the piezoelectric element transmits displacement of the piezoelectric element to the actuator base.